Plantronics Blackwire 500 C520-M USB Binaural Microsoft-Certified Version Headphone USB HEADSET: Hi-fi stereo USB headset with microphone (Blackwire 520) is ideal for those who want a richer, immersive experience. SMART SENSOR TECHNOLOGY: Intuitively manages calls and audio so you can answer a call by simply placing the mono headset on your head. COMFORTABLE DESIGN: Simple, intuitive, inline controls on the USB headset let you answer/end, mute, and control the volume of your calls with ease, while ultra-soft leatherette ear cushions and lightweight headband means all-day comfort and a secure fit. DYNAMIC EQ: Microphone headset with dynamic EQ feature optimizes your voice quality when on calls and automatically adjusts the EQ settings when youre listening to music or multi-media playback COMPATIBILITY: Plantronics headset is built to work with Amazon Connect, Chime and other UC applications and softphones from Microsoft, Avaya, Cisco and others.